Piezo ignition devices fitted to open-air cooking apparatus for igniting the burner of said apparatus are known, inter alia, from Swedish Patent Specification 9603139-8 (513 251). This patent publication teaches a piezo ignition device fitted as an ancillary at right angles to the burner-mixing pipe. The ignition spark is delivered to the upper side of the burner via an electrode located on the outside of the burner. The ignition device is activated by pressing a button, it being necessary to constantly “hold against” the opposite side, which requires the provision of means to protect against the heat generated by the apparatus. It may also be necessary to surround the ignition device with diverse protective plates in order to protect against the heat generated by the burner.
The U.S. Patent Specification U.S. Pat. No. 4,302,181 teaches a piezo ignition device for igniting a gas grill, wherein the device is applied with its power-effect in a direction parallel with the burner mixing pipe. However, this ignition device is activated by pressing the device upwards with one finger, therewith moving the device to an appropriate position in the burner in a first ignition stage, and thereafter by continuing to press the ignition device in the same direction in a second ignition stage, such as to produce an ignition spark. The applied upward pressure also means that it is necessary to “hold against” the grill with this type of ignition device, so as to prevent the grill from being lifted in its entirety as a result of the finger pressure applied to the device.
It is therefore necessary with both of these earlier known gas mixture ignition devices to activate a counter-pressure device which functions to exert an oppositely directed force, in order to control ignition of the cooking apparatus.